When he first meets Leto he says that he has been commanded to betray the Duke---but if he really had gone native why would he ever join a conspiracy to engineer a return of the harkonens, so hated by the fremen?

UPDATE 2: ethan fremen says, "Note that randomnumbers. info has greater claim on being" truly random "because it generates a single random number from a single quantum event while hot bits times the difference between two paired decay events in order to generate a single bit."